In hemodialysis application wherein, a blood is withdrawal from a blood vessel for treatment by an artificial kidney device and the treated blood is introduced back into blood vessel.
Various known catheters have been employed to withdrawal a blood from a blood vessel through one lumen of the catheter, then the dialyzed blood is returned to the patient through a second lumen of the catheter.
The most common designs for distal tip of hemodialysis catheters are step-tip, split-tip, symmetric-tip and self-centric curved split-tip. Symmetric-tip catheters have become alternative to conventional step-tip and split-tip catheters for their ability to reverse blood lines during dialysis without an increase in recirculation.
For self-centric curved split-tip catheter, it was designed to automatically center the catheters ports within a blood vessel to reduce fibrin sheath formation, thrombosis and vessel wall occlusions by keeping the tips of the catheter away from the blood vessel wall.
Still there may be drawbacks for above catheters, for example for symmetric-tip catheters, coherent patterns of laminar flow become disrupted by a blood flowing in a direction opposite to a main direction of flow, forming a low-velocity recirculation eddy. The resultant stagnation of a bloodstream can promote thrombus formation and development. Another example of drawback with self-centric curved split-tip catheter is a recirculation in a reverse blood lines configuration which may be more than 20%.
Therefore, it would be desirable to design catheters to may utilize the features of symmetric-tip and self-centric curved split-tip catheters and may reduce the above drawbacks.